nicotinic receptor alpha-9; neuronal acetylcholine receptor subunit alpha-9; nicotinic acetylcholine receptor subunit alpha 9; NACHR alpha 9 (CHRNA9, NACHRA9)

Function

• nicotinic receptor alpha subunit
• subunit of ionotropic receptor with probable role in modulation of auditory stimuli
• channel associated with receptor is permeable to a range of divalent cations including Ca+2, the influx of which may activate a K+ current which hyperpolarizes the cell membrane
• in the ear, this may lead to a reduction in basilar membrane motion, altering the activity of auditory nerve fibers & reducing the range of dynamic hearing
• this may protect against acoustic trauma
• may also regulate keratinocyte adhesion
• can form homo- or hetero-oligomeric channels in conjunction with CHRNA10
• the native outer hair cell receptor may be composed of CHRNA9-CHRNA10 hetero-oligomers
• the CHRNA9-CHRNA10 hetero-oligomer has an atypical pharmacological profile, binding several non-nicotinic ligands including:
  • strychnine (glycine receptor antagonist)
  • atropine (muscarinic acetylcholine receptor antagonist)

Structure

• belongs to the ligand-gated ionic channel (TC 1.A.9) family

Compartment

• cell junction, synapse, postsynaptic cell membrane

Expression

• expressed in cochlea, keratinocytes, pituitary gland, B-cells & T-cells

More general terms

• nicotinic receptor alpha

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:5558
• OMIM: https://mirror.omim.org/entry/605116
• UniProt: http://www.uniprot.org/uniprot/Q9UGM1.html